Supporting-arm for radial drills.



W. T. SEARS.

SUPPORTING ARM FOR RADIAL DRILLS.

APPLICATION NLBD 001212, 1912,

'lgl a Patented Feb. 10, 1914. V3

Wrtmarm T. ornanrronn, CONNECTICUT, Ass'IeNon rro `ritrarre av WHITNEYCOMPANY, or Haarroan, coNNnCrIoUT, A CORPORATION oF'Nnw JERSEY.

screenwriter-ARM ron RADIAL nations Specification of Letters Patent.

, Patented-Feo l0, gd.

` Application sled october 1a, 1912. n semaine. 725,415.. y

To all whom it may concern l Be it known that I, IVILLARD T SEARS, acitizen of the United States, yresiding at. Hartford, in the county ofHartford and State of Connecticut, have invented certain new and usefulImprovements in Supporting-Arms for Radial Drills, of which thefollowing isa specification.

This invention relates to radial drillsl and more especially to Athesupporting arms thereof which sustain the spindle-carrying head. Thesesupporting arms during work, are subjected to considerable twistingstrains and various vmeans have been provided heretofore, for resistingthe same.

Onejway of accomplishing this particular result-has been to malte thesupporting arm in two laterally-spaced sections, the thrust insultingfrom the action of the drill being applied equally to these twosections. This isa-n ideal thrust-resisting arm and practicallyeliminates the evils resulting from torsion; it is objectionable,however, in that the mechanism for adjusting the head and the spindle.is situated some distance from the tool, making it quite unhandy forthe' operator who frequently has to shift his hands from said adjustinglmechanism to. the tool-and vice versa. I provide a construction where Isecure the advantage of a sectional type of supporting arm without theobjection to which I have alluded, in, that the adjusting mechanism isin close proximity to the tool.

In the drawing accompanying and forming part of the presentspecification I illustrate in cross section one of the several forms ofembodiment of the which to enable those skilled in the art to practisethe same will be fully set forth .in the following description. I do notrestrict myself to this disclosure; I may depart therefrom in severalrespects within the scope of the invention defined by the claimsfollowing said description.

, A radialdrill ordinarily comprises a vertical column and ahorizontally-disposed arm ext-ending therefrom, said arm supporting theadjustable head `which carries the rotary drill-spindle. The arm shown1n the drawings has the laterally-spaced or separated thrust-receivingsections 2 and 3, which as shown are hollow, an advantaJ geous thoughnot essential construction.' Asshown the section 2 is 'deeper than thecom'- invention two being opposite side of saidv head'is equipped withan upwardly i the terminal portion of which is flattened to engage andslide upon thetlat bearing face or wav 9, near the lower portion of thesection Itwill be observed that the bearing contact ofgthe rib or fin I5is a less distance from the center of upward thrust of thel tool than isthe bearing contact of the horn orA projection 8, said center beingcoincident with the axis of rotation of the spindle il. Naturallytherefore the amount of upward thrust applied to the section 3 is lessthan that applied to the section 2, and in practice the difference inthrust or leverage applied willv correspond practically ing arm, thesection 2 being of greater resisting power than the section 3. Owing tothe fact that the lower portion of the section 3 is some distancer abovethe correspending portion of the section '2 I provide ample space inwhich to receive and accommodate the adjust-ing mechanism for the head 4and spindle 4l and at the same time provide that such mechanism beclosely adjacent to the tool or drill, thus materially simplifying andreducing the work of the operator.

While the two sections of the arm receive the upward thrust of thedrill, transmitted thereto through the spindle 4X, and head 4, said headin the construction shown (although not essential) is sustained whollyby or from the deeper and greater thrust-resisting section 2. A tension12 of L shape, the pendent branch of which fits against the bearingsurface 13 head. It should be noted that while the difcurved horn or.lprojection 8,

on said'section 2 to 'prevent tippingof said lined therein by theremovable gib 7. The

with .the difference in vertical resisting power of the two sections ofthe supportico spindle 4 Afor longitudinally adjusting saidl spindle. Itwill be seen that the distance between this arm or lever 10 and the toolend of the spindle 4 is quite small.

What I claim is:l

1. A supportingarm for radialdrills, comprising two laterally-spacedsections of different depths, the section of greater depth extendingbelow the section of less depth,Z and a spindle-carrying head betweensaid sections, having a thrust contact with both said sections, thepoint of thrust contact'-` the section of less depth being ai the axisof rotation of against greater distance from the spindle than the pointof thrust contact against the section of greater depth.

2. A supporting arm for radialdrills, comprising two laterally-spacedsections of different depths, the upper portions of which areapproximately in horizontal alinement, the section of greater depth4extending below the section of less depth, and a spindle-carrying headbetween said sections, having a lever l() fastened to thev lower' thrustcontact with both said sections, the point of thrust contact against thesection of vless depth being a greater distance from the axis ofrotation than the point of thrust oontact against the section of greaterdepth.

3. A supporting arm for radial drills comprising laterally spacedsections of different thrust-receiving ability, and a spindlecarryinghead having a spindle between the sections of the arm, having a thrustcontact with .both sections, the points of thrust contact against saidsections being disposed at such distance from the axis of thespindle-.as to cause said head to apply an upward thrust v to each ofsaid sections approximately in proportion with the thrustreceivingability thereof.

4f. A supporting arm for .radial drills, comprising laterally-spacedsections of different thrust-receiving ability, and a spindle-carryinghead between the sections of the arm, having a thrust contact with bothsections, the point of thrust .contact against the section of lessthrust-receiving ability being a greater distance from the axis ofrotation of the spindle than the point of thrust contact of the sectionof 1g-seater thrust-receiving ability.

In testimony when. f" aix my signature in presence of two w losses.

^ .Will JA'LD T. SEARS. Witnesses:

HEATH SUTHBRMND,

M. Stro-naa

